An analysis of architecture of videoconferencing system based on concept of active network

Guaranteed QoS transmission can be performed using signalling reservation protocols, as RSVP. In some situations, if (due to limited network resources) reservation is difficult or impossible, a change of transmitted traffic parameters will be necessary. The RTP protocol recommendation permits translation mechanisms to change transmitted stream parameters on the local network boundary. RTP transcoders adaptively change parameters of the stream based on current network state and end-user requirements. In the paper the architecture of videoconferencing systems with integrated end-to-end QoS management is presented. The proposed QoS management is based on distributed measurements carried out by mobile agents and consists of, between others, a set of transcoding agents located in the network nodes.